Portable roll picker



Original Filed Oct. 11, 1965 Elli 2 2K) 8 4 4 Q- w m v M W? n INVENTOR.EDWARD E. HART W f%r ATTORNEY United States Patent 3,316,428 PORTABLEROLL PICKER Edward E. Hart, Springfield, Ohio, assignor to GlobeIndustries, Inc., Dayton, Ohio, a corporation of Ohio Continuation ofapplication Ser. No. 315,630, Oct. 11, .1963. This application Oct. 31,1966, Ser. No. 591,030 2 Claims. (Cl. 310-51) This application is acontinuation of Ser. No. 315,630, filed Oct. 11, 1963 and is nowabandoned.

This invention relates to a portable rotary tool which includes arotating shaft or spindle for removing very loosely packed accumulationsof lint from textile machinery.

Devices of the type with which the invention is concerned are referredto as roll pickers and generally consist of some motive power whichdrives a long, smooth, tapered spindle or shaft of small diameterrotating at a relatively high speed, e.g., 12,00015,000 r.p.m. As iswell-known, lint, if allowed to accumulate on rotating members oftextile machinery, tends to pack very tightly and eventually will forceits way inside bearing journals and other critical areas, thus causingdamage to the machine or ruining spools of thread. The roll pickeroperates in such manner that the rotating spindle is surrounded by aboundary layer of air which when placed adjacent the lint carryingrotating member of the textile machine will serve to catch the lightouter fibers of the accumulatedblanket of lint. Since the blanket oflint on the textile machinery roll is composed of fibers alighting atrandom on the machine, it is essentially interwoven throughout, and theouter fibers, once caught up by the rotating spindle, will serve toremove the entire blanket from the section of the machine. The lint,thus removed from the machine, is then discarded and the roll picker isagain made available for continued operation. I

Such devices as above described have customarily been operated fromcompressed air sources, with the attendant disadvantage that longtrailing air hoses must be attached to the device as the operatorprogresses down the line of textile machines. Obviously, such tools whenair driven have the disadvantage of presenting a safety hazard due tothe trailing hoses, and also of being somewhat cumbersome in that theoperator must manipulate a tool having attached thereto a relativelyheavy hose.

It is therefore one object of the invention to provide a roll pickercapable of portable operation, and which has all of the advantages ofair driven tools.

It has been found, in the use of roll pickers, that the operator willapply pressure to the tool as it is applied towards the rotating part ofthe textile machinery, instead of merely bringing it closely adjacentthereto. In the case of air driven tools, generally there is sufficientair pressure available to still continuously rotate the spindle at theproper speed so that the device operates. However, in the case ofportable devices where the power supply is generally limited, shouldpressure be applied on the roll picker and blade, the motor willgenerally lose speed and the device will cease to operate. Usually, whenthe motor is thus overloaded and slowed down, it will drain the powersource and perhaps damage it.

After extended use of roll picker devices, it has been observed that thespindles or blades will become permanently bent out of shape, and uponoperation of the device, unwanted vibration or blade whipping willoccur. However, as indicated above, in the case of air driven unitsthere is generally suflicient power available to drive the unit throughthe whipping or vibrating condition, or alternatively, the vibration canbe damped out by wiping the blade with the hand. In the case of portabledevices, generally the power supply is so limited that insufficientpower is available to drive the spindle through its vibrating condition.In the case where an electric motor is mounted in a portable device torotate the blade, I have found that the first mode resonant frequency ofblades is close to the no load motor speed, and thus the slightesteccentricity of the blade tip will cause the blade to begin vibrating asthe motor comes up to speed. As the motor approaches maximum speed, theblade goes into resonance and the amplitude is great enough so that theinduced load will not permit the motor to pull through this speed, hencemaintaining the whipping condition. As indicated above, motor currentalso becomes excessive, thus causing either rapid deterioration of thepower source or premature burning out of the brushes. It is therefore afurther object of the invention to provide a portable roll pickerproviding means whereby eccentricity of the blade tip will not causedestruction of the motor or its power supply.

I have found in the case of portable battery operated roll pickers thatthe battery will excessively discharge unless some type of relay deviceis incorporated into the circuit which will open the circuit when thebattery potential drops below a given value, and close the circuit whenit rises above a slightly higher value. The problem with such relaydevices is that there is no commercially available relay small enough toconveniently be employed in a hand-carried roll picker. I have furtherdetermined 1 that the pull-in to drop-out ratio of relays commerciallyavailable is so high that such relays cannot operate over a smallvoltage range comprising only a slight differential between drop-outvoltage and pull-in voltage. It is therefore a still further object ofthe invention to provide a voltage protection circuit in a roll pickerfor a portable battery, enabling the preservation of long battery life.

These and further objects of the invention will become more readilyapparent upon a reading of the description following hereinafter, andupon an examination of the drawings, in which:

. 'FIG. 1 represents a cross-sectional view through the device of theinvention;

FIG. 2 represents one voltage control circuit for the roll picker;

FIG. 3 represents a modified control circuit similar to that of FIG. 2;and

FIG. 4 is a schematic illustrating a preferred voltage control circuitfor the roll picker of the invention.

As indicated above, the problem of unwanted vibration or whipping of theblade in a roll picker becomes acute when it is attempted to provide aportable electric motor driven battery operated device. The primaryfactor causing this problem is that due to the high speed motors whichmust necessarily be employed, the first mode resonant frequency ofrelatively short blades is close to the no load motor speed. Theslightest eccentricity of the blade tip (i.e., as would be caused byordinary handling of the device) causes the blade to begin vibrating asthe motor comes up to speed. As the motor approaches maximum speed, theblade goes into resonance and the amplitude becomes so great that theinduced'load will not allow the motor to pull through this speed, so thewhipping condition is sustained. During this condition, the motor willdraw excessive current. I have found that by placing O-rings around themotor frame and mounting it to the case through an elastic mounting,while otherwise permitting freedom of motion within the case, serves toisolate the motor from the case or handle. This allows the motor to movewhen the blade starts going into resonance, thus damping it outsufficiently for the motor to continue its speed build-up and pullthrough the critical speed.

Referring now to FIG. 1, it is seen that the motor 4 is mounted withinthe case 2 of a roll picker 1. The motor 4 is coupled to a blade orspindle 3 which is shown as being tapered. The coupling between themotor and the spindle is accomplished by a connector member 6 which ismounted on the motor shaft as by the set screw 7, and to the spindle 3as by the set screw-8. .The motor 4 is comprised of a rotating armature42 and the stator 28, and may be of the permanent magnet or wound fieldD.C. type. The armature 42 is provided with a commutator and brushes 24and 26 as will be understood by those skilled in the art.

Power to the motor 4 is provided by the electrical cord 14 which ismounted through the rear end of the case 2 through a grommet to thebrushes 24 and 2 6, r'espec tively. The lead is connected to apush'button switch 18 which also has connected to it the lead 16 of thesupply line 14.

The motor 4 is mounted within the case 2 by a pair of O-rings 30 and 32,and by the screw 34 which is threaded into the case of the motor at 40.The screw 34 is mounted within a sleeve 36 of preferably stiff material,which sleeve in turn is surrounded by a sleeve 38 of elastic material.Sufi'icient clearance is provided between the motor 4 and the case 2 sothat upon operation of the device and the commencement of anyvibrations, the elastic mounting of the motor within the case willquickly dampen out such unwanted vibrations.

As indicated above, it is desirable that as the portable battery losesits power, there comes a point where power from the power supply bedisrupted to the motor. This is brought about by the provision of acontrol circuit located within the space 9 of the case 2. This controlcircuit is so designed that when the power available from the powersupply drops below a predesignated point, the circuit is opened to themotor, and should the battery recover sufficiently to a higher level,then the circuit will again be closed to provide power to the motor. Thehappening of this on/oif cycle will serve as a warning signal to theoperator to replace and/ or recharge the battery immediately. One suchcontrol circuit is indicated in FIG- URE 2 wherein the battery 44supplies power to the motor armature 42 through the lines 20 and 22. Theswitch 58 is a push-button switch similar to the switch 18 of FIG. 1.When the switch 58 is closed, then current will flow from the battery 44through lines 46 and 56 through coil 52. The zener diode 5-4 is sochosen that a minimum voltage must be available from the battery 44before current will flow through the circuit (i. e., the zener level).When current flows through coil 52, sufficient flux is created to closethe reed switch 50, thus permitting current to flow through lines 22 and20 to the motor armature 42. As the battery 44 discharges, then thecurrent will fall below the zener level of diode 54, thus blocking flowthrough lines 46 and 56. When current ceases to flow through lines '46and 56, then coil 52 will no longer be enabled to hold the reed closed.When this occurs, then the reed 50 will open to remove power from themotor armature 42.

Although under ordinary circumstances the circuit of FIG. 2 will proveto be sufiicient, it has been found that with particular power supplieshaving high recovery rates, and with high speed motors of custom design,the battery 44 will quickly recover to raise the voltage level above thezener level and thus reactivate the switch 43. This action will beimmediately followed by a high surge of current of the motor whenre-energized to immediately again lower the potential below theoperating range of the zener diode 54 and the circuit is again caused toopen. This action cycles at a very high rate which quickly pits thereeds of switch 48 and latches them closed. When the reeds are struck,the push-button switch 58 could be released, but would no longer controlthe motor. In order to overcome such disadvantage the arrangement ofFIG. 3 may be employed. In this circuit the switch 58 is placed inseries with the armature 42 leads 20 and 22, so that regardless of whathappens to the reed 50 of the switch 48, the power to the motor armature42 may still be disconnected by releasing the push-button switch 58. Inthis circuit when the push-button switch 58 is initially depressed andthe power supply 44 is of a potential which exceeds the zener level ofzener diode 30, then current will flow through line 82, through zenerdiode 8t) and resistance 78 to create the proper bias on the base 76 oftransistor 70 to turn the transistor (in; When the transistor 70 isturned on, then current will be enabled to how through line 22 andthrough the emitter to collector path 72-74 of transistor 70. It isnoted that instantaneously prior to the time that the efriittercollector path of transistor '70 is closed, current will flow throughthe base collector path 74-, 76 of transistor 70 to pass current throughcoil 52 and close the switch 48 by drawing the reed 50 closed. Thisinstantaneous delay prevents any surge current from damaging thetransistor 70. Also, since only small amounts of power are required toturn transistor 70 on, the cost of the several components may be reducedby employing lower cost zener diodes.

Even though the circuit of FIG. 3 may be employed to remove thepossibility of current continuing to flow through the armature 42 whenthe push button 58 is released, it is still found that should theoperator not realize what is occurring (usually the cycling of the reeds50 will cause an audible buzzing in the instrument), then the operatorwill continue to depress push button 58 and cause the motor failureproblem indicated above. To avoid such shortcomings, the circuit of FIG.4 is prefer ably employed. In this preferred embodiment the pushbuttonswitch 58 is again employed in series with the motor armature 42 vialeads 20 and 22 from the battery 44. However, a pair of transistors 162and 13?) are em ployed in the following manner. With both transistorsturned off, the push button 58 is depressed, and in the event the powersupply 44 is of a potential which exceeds the zener level of the zenerdiode 110, then current will flow through the base emitter path 160408of the tran-" sistor 102 to turn the transistor 10-2 on. Whentransistor' 102 is turned on then current will flow through its emittercollector path 194-106, through line 118 and through} coil 50. Whencurrent passes through coil 50 the read 5 2 is drawn to close the switch48 and permit current to flow to the armature 42. A capacitor 122 isemployed in a shunt path to minimize arcing of the feed 52.- As thepower supply 44 discharges, the potential in line 112 will fall belowthe zener level of zener diode 116, thus removing the bias on the base108 of transistor 102 and turn it off. When transistor 102 is turnedoff, cur rent will no longer flow in line 118 so that the switch 48 willbe opened to remove power from the motor arma-' ture 42. In order toprevent the cycling of the reed 52 as discussed above when the powersupply 44 momentarily recovers, a positive latch out action isaccomplished by the provision of the second transistor 130. As long asswitch 58 remains closed, although switch 48 is opened by the actionjust described to remove power from the armature 42, current will stillflow from the battery 44 through the emitter collector path 134-136 oftransistor 130. The transistor ordinarily is turned off when thetransistor 102 is turned on because of the values of resistances 116,114 and 126. For example, the resistance 114 may be five or six timesthat of resistance 116, whereas the resistance 126 may be five or sixtimes that of 114, and consequently 30 times that of resistance 116.With such a selection of components, when transistor 102 is turned oncurrent will be prevented from flowing past resistance 126 through lead118. However, once transistor 102 is turned off, then the capacitor 142which has previously been charged up will be permitted to dis-charge,thus imposing a bias upon the base 132 of transistor 130 to turn it on.Current will thereafter flow from power supply 44 through the closedswitch 53, the emitter collector path 134 136 of transistor 130,resistance 116 back to the negative terminal of battery 44. As long asswitch 58 remains depressed, the transistor stays on and it is onlyturned off when the switch 58 is opened to remove the bias on base 132of transistor 130. Thereafter, when switch 58 is depressed, and in theevent the power supply 44 does not provide a potential which exceeds thezener level 110, no current will flow in either circuit of transistor130 or 102. Upon the substitution of a properly charged power supply 44,when switch 58 is activated then the proper potential is available toexceed the zener level of zener diode 110 and transistor 102 is turnedon as indicated above. In this manner pitting of the reed 52 of theswitch 48 is avoided regardless of the inattention of the operator.

Although various specific embodiments have been described above, it willbe readily understood by those skilled in the art that variousrearrangements of parts and modifications of parts may be accomplishedwithout departing from the spirit and scope of the invention as definedin the appended claims.

What I claim is:

1. A portable battery operated roll picker comprising, in combination:

a hollow elongated housing open on one end thereof adapted to be handheld,

a high speed electric motor operating at a speed of at least 10,000r.p.m. mounted coaxially at the open end of said housing, and having anoutput shaft protruding from said open end of said housing,

an elongated spindle member mounted to the motor output shaft andextending coaXially with said housing, said spindle member having afirst mode resonant frequency substantially within the range of the noload motor speed and when driven above said resonant frequency serves tostrip lint from textile machinery rolls, and

elastic vibrating damping mounting means encircling 0 said motor forholding and retaining said motorspindle assembly with respect to saidhousing in spaced relationship therefrom to provide the sole supporttherefor and permitting restricted relative movement of the motor withrespect to the housing at or near the resonant frequency of the spindlemember while preventing physical contact of the motor with said housingand damping out motor and spindle vibration sufficiently to enable themotor to run through the critical speed.

2. The portable battery operated roll picker of claim 1 wherein saidelastic vibration damping mounting means comprises a member affixed tosaid motor and protruding through said opening in said housing, saidprotruding member being surrounded by a yieldable element extendingbetween said housing and said member.

No references cited.

MILTON O. HIRSHFIELD, Primary Examiner. J. W. GIBBS, Assistant Examiner.

1. A PORTABLE BATTERY OPERATED ROLL PICKER COMPRISING, IN COMBINATION: AHOLLOW ELONGATED HOUSING OPEN ON ONE END THEREOF ADAPTED TO BE HANDHELD, A HIGH SPEED ELECTRIC MOTOR OPERATING AT A SPEED OF AT LEAST10,000 R.P.M. MOUNTED COAXIALLY AT THE OPEN END OF SAID HOUSING, ANDHAVING AN OUTPUT SHAFT PROTRUDING FROM SAID OPEN END OF SAID HOUSING, ANELONGATED SPINDLE MEMBER MOUNTED TO THE MOTOR OUT-PUT SHAFT ANDEXTENDING COAXIALLY WITH SAID HOUSING, SAID SPINDLE MEMBER HAVING AFIRST MADE RESONANT FREQUENCY SUBSTANTIALLY WITHIN THE RANGE OF THE NOLOAD MOTOR SPEED AND WHEN DRIVEN ABOVE SAID RESONANT FREQUENCY SERVES TOSTRIP LINT FROM TEXTILE MACHINERY ROLLS, AND ELASTIC VIBRATING DAMPINGMOUNTING MEANS ENCIRCLING SAID MOTOR FOR HOLDING AND RETAINING SAIDMOTORSPINDLE ASSEMBLY WITH RESPECT TO SAID HOUSING IN SPACEDRELATIONSHIP THEREFROM TO PROVIDE THE SOLE SUPPORT THEREFOR ANDPERMITTING RESTRICTED RELATIVE MOVEMENT OF THE MOTOR WITH RESPECT TO THEHOUSING AT OR NEAR THE RESONANT FREQUENCY OF THE SPINDLE MEMBER WHILEPREVENTING PHYSICAL CONTACT OF THE MOTOR WITH SAID HOUSING AND DAMPINGOUT MOTOR AND SPINDLE VIBRATION SUFFICIENTLY TO ENABLE THE MOTOR TO RUNTHROUGH THE CRITICAL SPEED.